J. Allen Hynek is known as the father of modern UFO theory and authored three books (The UFO Experience: A Scientific Inquiry (Collector's Library of the Unknown); The Hynek UFO report; and The Hynek UFO Report: What the Government Suppressed and Why) and coined the phrase "close encounters of the third kind."
Mark O'Connell has just released a biography of Hynek called The Close Encounters Man: How One Man Made the World Believe in UFOs and he's with Lee Hay.